@Kristine-And-Sean0 Hosts who do their own cleaning eventually become experts in removing every kind of stain imaginable to preserve those towels and sheets. I'm not sure what the magic pre-treatment for this particular product is, but what works on hair dye stains is a 1:2 mix of hydrogen peroxide and dish soap.
House Rules are most effective when they aren't bogged down with the little things, and anyway, there are so many different skin and hair products that leave annoying stains that it's a lost cause trying to micromanage guests' use of them. (My pet peeve has long been cleaning up after people with long hair that embeds itself in everything, but unfortunately a BALD GUESTS ONLY rule wouldn't be viable).